Surface treatment of fluorinated contact lens materials

• US 6,550,915 B1
• Filed: 12/21/1998
• Issued: 04/22/2003
• Est. Priority Date: 12/21/1998
• Status: Expired due to Fees

• Current Assignee: Bausch & Lomb Incorporated (Bausch Health Cos., Inc.)
• Original Assignee: Bausch & Lomb Incorporated (Bausch Health Cos., Inc.)
• Inventors: Grobe, George L. III
• Primary Examiner(s): Wilson, D. R.
• Application Number:
  US09/219,500
• Time in Patent Office: 1,583 Days
• Field of Search: 525/326.2, 525/326.4, 525/338, 525/388, 351/160.H
• US Class Current: 351/160.00H
• CPC Class Codes: C08J 7/12 Chemical modification
• CPC Class Codes: C08J 7/123 Treatment by wave energy or particle radiation C08J7/18 takes precedence
• CPC Class Codes: C08L 45/00 Compositions of homopolymers or copolymers of compounds having no unsaturated aliphatic radicals in side chain, and having one or more carbon-to-carbon double bonds in a carbocyclic or in a heterocyclic ring system; Compositions of derivatives of such polymers of cyclic anhydrides or imides C08L35/00; of cyclic esters of polyfunctional acids C08L31/00
• CPC Class Codes: C08L 83/08 containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
• CPC Class Codes: G02B 1/043 Contact lenses
• CPC Class Codes: Y10T 428/21 Circular sheet or circular blank
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers

Abstract

Hydrogen-plasma modification of a contact lens made from a fluorinated polymer reduces the surface chemistry of by removing fluorine, leaving behind a carbon-enriched surface that is further plasma processed into a hydrophilic surface for a lens material to be inserted into the ocular environment.

Claims

1. A method for treating the surface of a fluorinated contact lens material comprising the following steps:

(a) plasma treating the lens with a hydrogen-containing atmosphere for a total time period of at least 2 minutes, at a wattage of greater than 25 watts and a pressure of 0.1 to 1.0 torr, to reduce the fluorine content by at least 25 percent over the first 74 angstroms of the surface as determined by x-ray photoelectron spectroscopy (XPS) analysis; and

subsequently

(b) oxidizing the surface with an oxygen or nitrogen-containing gas or gaseous mixture, thereby increasing the wettability or biocompatibility of the lens.

2. The method of claim 1, wherein the plasma treatment in step (a) is between 25 and 1000 watts for a total time period of 2 to 60 minutes.

3. The method of claim 1, wherein the fluorinated contact lens material is the polymerization product of a mixture comprising a fluorine-containing silicone monomer.

4. The method of claim 3, wherein the monomer is a poly(organosiloxane) capped with an unsaturated group at two ends containing a fluorinated side group.

5. The method of claim 4 wherein the monomer contains a pendant fluorinated alkyl group containing a —

CHF₂ or —

CF₃ end group.

6. The method of claim 4, wherein the monomer comprises a fluorinated derivative of a polysiloxanylalkyl (meth)acrylate monomer.

7. The method of claim 1, wherein the lens is made from a monomer mixture comprising a perfluorinated monomer.

8. The method of claim 1, wherein the fluorine content or C—

F bonding content is reduced by at least 50 percent over the first 74 å

ngstroms of the surface as determined by XPS analysis.

9. The method of claim 1, wherein said oxidization of the surface results in an increase in the nitrogen and/or oxygen content by at least 5 percent over the first 74 å

ngstroms of the fluorinated contact lens material as determined by XPS analysis.